We present a combination of techniques to simulate turbulent fluid flows in 3D. Flow in a complex domain is modeled
using a regular rectilinear grid with a finite-difference solution to the incompressible Navier-Stokes equations.
We propose the use of the QUICK advection algorithm over a globally high resolution grid. To calculate pressure
over the grid, we introduce the Iterated Orthogonal Projection (IOP) framework. In IOP a series of orthogonal
projections ensures that multiple conditions such as non-divergence and boundary conditions arising through
complex domains shapes or moving objects will be satisfied simultaneously to specified accuracy. This framework
allows us to use a simple and highly efficient multigrid method to enforce non-divergence in combination with
complex domain boundary conditions. IOP is amenable to GPU implementation, resulting in over an order of
magnitude improvement over a CPU-based solver. We analyze the impact of these algorithms on the turbulent
energy cascade in simulated fluid flows and the resulting visual quality.